scholarly journals Transpiration and Normalized Difference Vegetation Index Response of Seashore Paspalum to Soil Drying

HortScience ◽  
2009 ◽  
Vol 44 (7) ◽  
pp. 2046-2048 ◽  
Author(s):  
Georgene L. Johnson ◽  
Thomas R. Sinclair ◽  
Kevin Kenworthy
Keyword(s):  
Plant Species ◽  
Transpiration Rate ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Leaf Gas Exchange ◽  
Organic Soil ◽  
Soil Drying ◽  
Seashore Paspalum ◽  
Consistent Response ◽  
Reflectance Measurements

A consistent response has been observed among many plant species in their leaf gas exchange as soils are subjected to a drying cycle; except for one case, these studies have not included turfgrass species. The current study reports the change in transpiration rate of six genotypes of seashore paspalum (Paspalum vaginatum Swartz) during soil drying when grown on either an organic soil or sand. On organic soil, the response was consistent with results with other plant species in that there was no decline in transpiration rate until the fraction of transpirable soil water (FTSW) reached the range of 0.25 to 0.31. The decline in transpiration rate when plants were grown on sand occurred in the FTSW range of 0.10 to 0.17, which was also consistent with reports for other species when grown on sand. The lower FTSW for the decline in transpiration rate on sand appears to be a result of the greater retention of water in fully wetted sand in pot experiments as compared with field conditions. Because the decline in transpiration occurred at a higher FTSW in ‘SeaIsle Supreme’, ‘Aloha’, and ‘SeaIsle 1’ than in ‘SeaIsle 2000’, this is an indication that these genotypes are water-conserving and may be better suited to water-deficit conditions. Quality changes in these grasses were monitored daily during the drying cycle by reflectance measurements of their normalized difference vegetation index (NDVI). No change in NDVI was observed for grasses grown on either soil type until the soil had become very dry and transpiration had decreased to low rates.

Decreased photosynthetic efficiency in plant species exposed to multiple airborne pollutants along the Russian-Norwegian border

2000 ◽  
Vol 78 (8) ◽  
pp. 1021-1033 ◽  
Author(s):  
Ann Marie Odasz-Albrigtsen ◽  
Hans Tømmervik ◽  
Patrick Murphy
Keyword(s):  
Chlorophyll Fluorescence ◽  
Plant Species ◽  
Photosynthetic Efficiency ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Plant Cover ◽  
Mixed Forest ◽  
Airborne Pollutants ◽  
Fluorescence Measurements ◽  
Study Sites

Photosynthetic efficiency was estimated by chlorophyll fluorescence measurements (Fv/Fm) in 11 plant species growing along a steep gradient of airborne pollution along the Russian-Norwegian border (70°N, 30°E). Photosynthetic efficiency was positively correlated with environmental variables including annual temperature and a maritime gradient and was negatively correlated with the airborne concentrations of Cu, Ni, and SO2 from the Cu-Ni smelters. Photosynthetic efficiency in six plant species from the mixed forest, but not pine (Pinus sylvestris L.), and three species from the birch forest was inversely correlated with SO2 and the concentrations of Ni and Cu in lichens. Measurement of fluorescence in these species was a sensitive indicator of pollutant impact. Plant cover at the 16 study sites and the photosynthetic efficiency of five target species correlated with normalized difference vegetation index (NDVI) values. This study demonstrated that it is possible to detect relations among field-measured ecophysiological responses in plants, levels of airborne pollutants, and satellite remote-sensed data.Key words: chlorophyll fluorescence, smelters, sulfur dioxide, nickel, copper, normalized difference vegetation index (NDVI).

scholarly journals CANOPY REFLECTANCE MEASUREMENTS USED TO ESTIMATE LATE BLIGHT (PHYTOPHTHORA INFESTANS) INFLUENCE ON POTATO YIELD CANOPY REFLECTANCE MEASUREMENTS USED TO ESTIMATE LATE BLIGHT (PHYTOPHTHORA INFESTANS) INFLUENCE ON POTATO YIELD

2020 ◽  
Vol 13 ◽  
pp. 21-27
Author(s):  
Manuela Hermeziu
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Field Experiments ◽  
Block Design ◽  
Potato Yield ◽  
Planting Density ◽  
Canopy Reflectance ◽  
Reflectance Measurements

"The present study was conducted to investigate potato late blight (Phytophtora infestans) influence on leaf chlorophyll level using datasets extracted from multispectral data captured at the canopy level. Field experiments were carried out to the National Institute of Research and Development for Potato and Sugar Beet Brasov, Romania in 2014-2016 period. It was used a complete randomized block design with four replicates, two planting distances between plants on row (25 and 30cm) and different fungicides, control technologies. Normalized Difference Vegetation Index (NDVI) was introduced to achieve a spectral vegetation index that can separate the vegetation from the uncovered ground. It is defined as the ratio between the infrared bands-red differences and sum them. Due to the different growth conditions, the effects of resulting variants from combinations of factors -varieties-planting density-late blight control technology-on the tubers yield have manifested with different intensity. In two of three years, the average NDVI value of plants grown at a density of 53.3 thousands hill/ha was significantly lower than the values determined at a density of 44.4 thousands hill/ha (NDVI 0.817 compared to 0.859 in 2014 and 0.905 compared to 0.895 in 2015). The correlation between the average values of NDVI yields and tubers were positive."

scholarly journals Hyperspectral field reflectance measurements to estimate wheat grain yield and plant height

2006 ◽  
Vol 63 (2) ◽  
pp. 130-138 ◽  
Author(s):  
Alexandre Cândido Xavier ◽  
Bernardo Friedrich Theodor Rudorff ◽  
Mauricio Alves Moreira ◽  
Brummer Seda Alvarenga ◽  
José Guilherme de Freitas ◽  
...  
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Narrow Band ◽  
Broad Band ◽  
Growth Stages ◽  
Sensing Applications ◽  
Field Reflectance ◽  
Reflectance Measurements

Hyperspectral crop reflectance data are useful for several remote sensing applications in agriculture, but there is still a need for studies to define optimal wavebands to estimate crop biophysical parameters. The objective of this work is to analyze the use of narrow and broad band vegetation indices (VI) derived from hyperspectral field reflectance measurements to estimate wheat (Triticum aestivum L.) grain yield and plant height. A field study was conducted during the winter growing season of 2003 in Campinas, São Paulo State, Brazil. Field canopy reflectance measurements were acquired at six wheat growth stages over 80 plots with four wheat cultivars (IAC-362, IAC-364, IAC-370, and IAC-373), five levels of nitrogen fertilizer (0, 30, 60, 90, and 120 kg of N ha-1) and four replicates. The following VI were analyzed: a) hyperspectral or narrow-band VI (1. optimum multiple narrow-band reflectance, OMNBR; 2. narrow-band normalized difference vegetation index, NB_NDVI; 3. first- and second-order derivative of reflectance; and 4. four derivative green vegetation index); and b) broad band VI (simple ratio, SR; normalized difference vegetation index, NDVI; and soil-adjusted vegetation index, SAVI). Hyperspectral indices provided an overall better estimate of biophysical variables when compared to broad band VI. The OMNBR with four bands presented the highest R² values to estimate both grain yield (R² = 0.74; Booting and Heading stages) and plant height (R² = 0.68; Heading stage). Best results to estimate biophysical variables were observed for spectral measurements acquired between Tillering II and Heading stages.

scholarly journals Salinity Tolerance and Recovery Attributes of Warm-season Turfgrass Cultivars

HortScience ◽  
2019 ◽  
Vol 54 (9) ◽  
pp. 1625-1631 ◽  
Author(s):  
Manuel Chavarria ◽  
Benjamin Wherley ◽  
James Thomas ◽  
Ambika Chandra ◽  
Paul Raymer
Keyword(s):  
Salinity Stress ◽  
Salinity Tolerance ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Recovery Period ◽  
Warm Season ◽  
Shoot Biomass ◽  
Seashore Paspalum ◽  
Turf Quality ◽  
Elevated Salinity

As population growth places greater pressures on potable water supplies, nonpotable recycled irrigation water is becoming widely used on turfgrass areas including golf courses, sports fields, parks, and lawns. Nonpotable recycled waters often have elevated salinity levels, and therefore turfgrasses must, increasingly, have good salinity tolerance to persist in these environments. This greenhouse study evaluated 10 commonly used cultivars representing warm-season turfgrass species of bermudagrass (Cynodon spp.), zoysiagrass (Zoysia spp.), st. augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze], and seashore paspalum (Paspalum vaginatum Swartz) for their comparative salinity tolerance at electrical conductivity (EC) levels of 2.5 (control), 15, 30, and 45 dS·m–1. Salinity treatments were imposed on the grasses for 10 weeks via subirrigation, followed by a 4-week freshwater recovery period. Attributes, including turf quality, the normalized difference vegetation index (NDVI), canopy firing, and shoot biomass reductions were evaluated before and after salinity stress, as well as after the 4-week freshwater recovery period. Results showed considerable differences in salinity tolerance among the cultivars and species used, with the greatest tolerance to elevated salinity noted within seashore paspalum cultivars and Celebration® bermudagrass. In comparison with growth in 2.5-dS·m–1 control conditions, increased shoot growth and turf quality were noted for many bermudagrass and seashore paspalum cultivars at 15 dS·m–1. However, st. augustinegrass and some zoysiagrass cultivars responded to elevated salinity with decreased growth and turf quality. No cultivars that had been exposed to 30- or 45-dS·m–1 salinity recovered to acceptable levels, although bermudagrass and seashore paspalum recovered to acceptable levels after exposure to 15-dS·m–1 salinity. More severe salinity stress was noted during year 2, which coincided with greater greenhouse temperatures relative to year 1.

scholarly journals Effects of Morning and Afternoon Shade in Combination with Traffic Stress on Seashore Paspalum

HortScience ◽  
2003 ◽  
Vol 38 (6) ◽  
pp. 1218-1222 ◽  
Author(s):  
Yiwei Jiang ◽  
Robert N. Carrow ◽  
Ronny R. Duncan
Keyword(s):  
Soil Compaction ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Tissue Injury ◽  
Field Trials ◽  
Stress Index ◽  
Lower Stress ◽  
Seashore Paspalum ◽  
Athletic Fields ◽  
Band Index

Turfgrasses are often exposed to different shade environments in conjunction with traffic stresses (wear and/or compaction) in athletic fields within stadiums. The objective of this study was to assess the effects of morning shade (AMS) and afternoon shade (PMS) alone and in combination with wear and wear plus soil compaction on `Sea Isle 1 seashore paspalum (Paspalum vaginatum Swartz). The study was conducted using two consecutive field trials under sports field conditions from 9 July to 10 Sept. 2001 at the Univ. of Georgia Experiment Station at Griffin. “T” shaped structures constructed of plywood on the sports field were used to provide §90% morning and afternoon shade, respectively, and were in place for 1 year prior to data accumulation. A wear device and a studded roller device simulated turfgrass wear (WD) and wear plus soil compaction (WSC), respectively, to the shaded plots. Only minor differences in turf color, density, or canopy spectral reflectance were found between AMS and PMS under no-traffic treatments in both trials. Grasses under WD generally recovered faster than those exposed to WSC across all light levels, including full sunlight (FL), AMS, and PMS. AMS combined with WD treatment had an average 9% higher rating of color, 11% higher density, and 28% less tissue injury than that of PMS with WD at 7 days after traffic treatment (DAT). Compared to PMS with WSC treatment at 7 DAT, AMS with WSC had 12% higher rating of color, 9% higher density, and 4% less tissue injury. AMS with WD treatment exhibited 11% higher normalized difference vegetation index (NDVI), 4% higher canopy water band index (CWBI), and 13% lower stress index than that of PMS with WD at 7 DAT. AMS with WSC, relative to PMS with WSC, demonstrated 8% higher NDVI, 3% higher CWBI, and 8% lower stress index at 7 DAT. Re sults indicated that AMS (i.e., afternoon sunlight) had less detrimental influences than PMS (i.e., morning sunlight) on turfgrass performance after it was subjected to wear stress or wear plus soil compaction.

scholarly journals The Salinity Tolerance of Seeded-type Common Bermudagrass Cultivars and Experimental Selections

2018 ◽  
Vol 28 (3) ◽  
pp. 276-283 ◽  
Author(s):  
Mingying Xiang ◽  
Justin Q. Moss ◽  
Dennis L. Martin ◽  
Yanqi Wu
Keyword(s):  
Salinity Tolerance ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Cynodon Dactylon ◽  
Block Design ◽  
Seashore Paspalum ◽  
Green Cover ◽  
Salinity Levels ◽  
The Common ◽  
Common Bermudagrass

Turfgrass managers are using reclaimed water as an irrigation resource because of the decreasing availability and increasing cost of fresh water. Much attention, thereby, has been drawn to select salinity-tolerant turfgrass cultivars. An experiment was conducted to evaluate the relative salinity tolerance of 10 common bermudagrasses (Cynodon dactylon) under a controlled environment in a randomized complete block design with six replications. ‘SeaStar’ seashore paspalum (Paspalum vaginatum) was included in this study as a salinity-tolerant standard. All entries were tested under four salinity levels (1.5, 15, 30, and 45 dS·m−1) consecutively using subirrigation systems. The relative salinity tolerance among entries was determined by various parameters, including the normalized difference vegetation index (NDVI), percentage green cover determined by digital image analysis (DIA), leaf firing (LF), turf quality (TQ), shoot vertical growth (VG), and dark green color index (DGCI). Results indicated that salinity tolerance varied among entries. Except LF, all parameters decreased as the salinity levels of the irrigation water increased. ‘Princess 77’ and ‘Yukon’ provided the highest level of performance among the common bermudagrass entries at the 30 dS·m−1 salinity level. At 45 dS·m−1, the percent green cover as measured using DIA varied from 4.97% to 16.11% among common bermudagrasses, where ‘SeaStar’ with a DIA of 22.92% was higher than all the common bermudagrass entries. The parameters LF, TQ, NDVI, DGCI, VG, and DIA were all correlated with one another. Leaf firing had the highest correlation with other parameters, which defined its value as a relative salinity tolerance measurement for common bermudagrass development and selection.

scholarly journals Tomato Rootstocks Mediate Plant-Water Relations and Leaf Nutrient Profiles of a Common Scion Under Suboptimal Soil Temperatures

2021 ◽  
Vol 11 ◽  
Author(s):  
Steven T. Bristow ◽  
Leonardo H. Hernandez-Espinoza ◽  
Maria-Sole Bonarota ◽  
Felipe H. Barrios-Masias
Keyword(s):  
Hydraulic Conductivity ◽  
Stomatal Conductance ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Plant Biomass ◽  
Leaf Gas Exchange ◽  
Root Anatomy ◽  
Shoot Biomass ◽  
Root Hydraulic Conductivity ◽  
Soil Temperatures

Environments with short growing seasons and variable climates can have soil temperatures that are suboptimal for chilling-sensitive crops. These conditions can adversely affect root growth and physiological performance thus impairing water and nutrient uptake. Four greenhouse trials and a field study were conducted to investigate if rootstocks can enhance tomato performance under suboptimal soil temperatures (SST). In a controlled greenhouse environment, we exposed four commercial rootstocks (Estamino, Maxifort, RST-04-106-T, and Supernatural) grafted with a common scion (cv. BHN-589) to optimal (mean: 24°C) and SST (mean: 13.5°C) and compared their performance with the non-grafted BHN-589 cultivar. Several root and shoot physiological traits were evaluated: root hydraulic conductivity and conductance, root anatomy, leaf gas exchange, leaf δ13C, shoot C and N, and biomass. Under field conditions, the same five phenotypes were evaluated for canopy growth, normalized difference vegetation index (NDVI), leaf nutrients, biomass, and yield. Under SST, root hydraulic conductivity (Lp) and conductance (KR), stomatal conductance (gs), and plant biomass decreased. Hydrostatic Lp decreased more than osmotic Lp (Lp∗hyd: 39–65%; Lp∗os: 14–40%) and some of the reduced conductivity was explained by the increased cortex area of primary roots observed under SST (67–140%). Under optimal soil temperatures, all rootstocks conferred higher gs than the non-grafted cultivar, but only two rootstocks maintained higher gs under SST. All phenotypes showed greater reductions in shoot biomass than root biomass resulting in greater (∼20%) root-to-shoot ratios. In the field, most grafted phenotypes increased early canopy cover, NDVI, shoot biomass, and fruit yield. Greenhouse results showed that Lp∗os may be less affected by SST than Lp∗hyd and that reductions in Lp may be offset by enhanced root-to-shoot ratios. We show that some commercial rootstocks possess traits that maintained better rates of stomatal conductance and shoot N content, which can contribute toward better plant establishment and improved performance under SST.

scholarly journals Monitoring a Calcium Biofortification Workflow in an Orchard of Pyrus communis var. Rocha Applying Precision Agriculture Technology

2021 ◽  
Vol 3 (1) ◽  
pp. 3
Author(s):  
Cláudia Campos Pessoa ◽  
Diana Daccak ◽  
Inês Carmo Luís ◽  
Ana C. Marques ◽  
Ana Rita F. Coelho ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Precision Agriculture ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Leaf Gas Exchange ◽  
Plant Stress ◽  
Fluorescence Analysis ◽  
Gas Exchange Parameters ◽  
Use Of Resources ◽  
Negative Impacts

Smart farming techniques can be used to maximize food production. This can be achieved by the rapid detection of variations in crops and clever use of resources such as water and fertilizers, which might minimize crop stress through direct target practices. In an orchard located in the West region of Portugal (GPS coordinates 39°23′28.997″ N; 9°4′52.483″ W), a Ca biofortification workflow with seven foliar sprays of CaCl2 (4 kg ha−1 and 8 kg ha−1) was used to increase Ca contents in “Rocha” pear trees. During the biofortification process, an Unmanned Aerial Vehicle, synchronized by GPS, was used to characterize the orchard regarding its morphology (slope) and to monitor trees (NDVI—Normalized Difference Vegetation Index). These data were correlated with Ca content (assessed by X-ray fluorescence analysis) and photoassimilate synthesis (assessed by leaf gas exchange measurements). The orchard showed no major slopes and after four sprays with CaCl2, NDVI values revealed no major differences between the control and sprayed trees. Accordingly, leaf gas exchange parameters did not reveal negative impacts in the photoassimilate synthesis of the sprayed trees, although in the leaves Ca content significantly increased. The use of precision agriculture techniques in correlation with other analyses to assess plant stress is discussed.

Pemetaan Pulau Kecil Gelasa Kabupaten Bangka Tengah

2019 ◽  
Vol 2 (1) ◽  
pp. 11-14
Author(s):  
Wahyu Adi
Keyword(s):  
Coral Reefs ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Image Interpretation ◽  
Vegetation Coverage ◽  
Small Island ◽  
Shallow Waters ◽  
Small Islands ◽  
Seagrass Beds ◽  
Cover Density

Pulau Kecil Gelasa merupakan daerah yang belum banyak diteliti. Pemetaan ekosistem di pulau kecil dilakukan dengan bantuan citra Advanced Land Observing Satellite (ALOS). Penelitian terdahulu diketahui bahwa ALOS memiliki kemampuan memetakan terumbu karang dan padang lamun di perairan dangkal serta mampu memetakan kerapatan penutupan vegetasi. Metode interpretasi citra menggunakan alogaritma indeks vegetasi pada citra ALOS yaitu NDVI (Normalized Difference Vegetation Index), serta pendekatan Lyzengga untuk mengkoreksi kolom perairan. Hasil penelitian didapatkan luasan Padang Lamun di perairan dangkal 41,99 Ha, luasan Terumbu Karang 125,57 Ha. Hasil NDVI di daratan/ pulau kecil Gelasa untuk Vegetasi Rapat seluas 47,62 Ha; luasan penutupan Vegetasi Sedang 105,86 Ha; dan penutupan Vegetasi Jarang adalah 34,24 Ha.   Small Island Gelasa rarely studied. Mapping ecosystems on small islands with the image of Advanced Land Observing Satellite (ALOS). Previous research has found that ALOS has the ability to map coral reefs and seagrass beds in shallow water, and is able to map vegetation cover density. The method of image interpretation uses the vegetation index algorithm in the ALOS image, NDVI (Normalized Difference Vegetation Index), and the Lyzengga approach to correct the water column. The results of the study were obtained in the area of Seagrass Padang in the shallow waters of 41.99 ha, the area of coral reefs was 125.57 ha. NDVI results on land / small islands Gelasa for dense vegetation of 47.62 ha; area of Medium Vegetation coverage 105.86 Ha; and the coverage of Rare Vegetation is 34.24 Ha.

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